CSLB General Building (B) — All Questions

Before repainting a previously painted, chalky exterior stucco wall, what is the FIRST thing a painter should do to ensure adhesion?

• a.Apply two finish coats without priming
• b.Wash the surface to remove chalk, dirt, and loose material✓
• c.Sand the stucco smooth with 220-grit paper
• d.Spray a heavy fog coat of the finish color

Chalk and surface contamination prevent a new coating from bonding. Washing (often with a pressure washer or detergent solution) removes the chalky residue and dirt so the primer or paint can adhere. Painting over an unwashed chalky surface commonly leads to peeling.

What is the primary purpose of caulking gaps around window trim before painting?

• a.To add color contrast to the trim
• b.To increase the paint's gloss level
• c.To seal joints against water and air infiltration and create a smooth line✓
• d.To speed up the drying time of the topcoat

Caulk seals the joint between dissimilar materials such as trim and siding, keeping water and air out and preventing paint from cracking at the gap. A properly tooled caulk bead also gives a clean, continuous paint line. Paintable acrylic-latex caulk is typically used before priming or painting.

When patching a small nail hole in interior drywall, which sequence is correct?

• a.Fill with spackle, let dry, sand smooth, then spot-prime✓
• b.Prime the hole, then fill with spackle and leave unsanded
• c.Paint the hole first, then fill with caulk
• d.Sand the wall, then apply finish coat directly into the hole

Lightweight spackle is pressed into the hole, allowed to dry, then sanded flush with the surface. Spot-priming the patch seals the porous filler so the finish coat dries to a uniform sheen. Skipping the primer often causes 'flashing,' where the patch shows through as a dull spot.

Under the EPA Renovation, Repair and Painting (RRP) Rule, work that disturbs painted surfaces in housing built before which year generally triggers lead-safe requirements?

• a.1998
• b.1978✓
• c.1985
• d.1960

The RRP Rule applies to housing and child-occupied facilities built before 1978, the year lead-based paint was banned for residential use in the U.S. Firms disturbing more than the de minimis area of paint in these buildings must be certified and use lead-safe work practices. This protects occupants, especially children, from lead dust.EPA RRP Rule

Which work practice is REQUIRED by the EPA RRP Rule when disturbing lead-based paint in a pre-1978 home?

• a.Dry-sanding to keep dust airborne for easier cleanup
• b.Using an open flame torch to burn off the paint
• c.Containing the work area with plastic and cleaning with HEPA vacuuming and wet methods✓
• d.Sweeping debris into the yard for disposal

Lead-safe practices require containing the area with plastic sheeting, minimizing dust, and cleaning with HEPA vacuums and wet wiping. Open-flame burning and uncontrolled dry sanding are prohibited because they generate hazardous lead dust or fumes. A cleaning verification step confirms the area is safe before reoccupancy.EPA RRP Rule

What causes efflorescence, the white crystalline deposit sometimes seen on masonry and concrete?

• a.Excess paint sheen reacting with sunlight
• b.Water carrying soluble salts to the surface, where the water evaporates and leaves salt behind✓
• c.Sanding dust left on the wall
• d.Overheating of latex paint during curing

Efflorescence is water-soluble salt that migrates through masonry as moisture moves to the surface and evaporates. Painting over it traps salt and moisture, causing the coating to peel. The deposit must be removed (dry brushing or a masonry cleaner) and the moisture source addressed before coating.

Before painting new bare wood trim, why is sanding in the direction of the grain important?

• a.It smooths raised fibers without leaving cross-grain scratches that show through the finish✓
• b.It removes the need for any primer
• c.It increases the moisture content of the wood
• d.It darkens the natural color of the wood

Sanding with the grain levels raised fibers and creates a smooth surface without visible cross-grain scratch marks that telegraph through paint. Sanding across the grain leaves scratches that become obvious under a gloss finish. A dust-free, smooth surface improves both appearance and adhesion.

How should mildew on an exterior surface be treated BEFORE repainting?

• a.Paint directly over it with two coats of the finish
• b.Sand it off dry and leave the residue
• c.Kill and remove it by cleaning the surface, commonly with a bleach-and-water or dedicated cleaning solution, then rinse✓
• d.Cover it with clear caulk

Mildew is a living fungus; painting over it lets it grow through the new coating. It must be killed and washed off, often using a diluted bleach solution or a commercial mildew cleaner, followed by a thorough rinse. Using a mildew-resistant coating helps prevent regrowth in damp areas.

What tool or method best confirms whether a concrete slab is dry enough to coat?

• a.A visual glance at the surface color
• b.A moisture test such as a calcium chloride test or a plastic-sheet (ASTM D4263) test✓
• c.Touching the slab with a bare hand
• d.Smelling the surface for dampness

Concrete can look dry on the surface while retaining moisture that causes coating failure. A calcium chloride test measures moisture vapor emission rate, and a taped plastic-sheet test reveals trapped moisture as condensation. Coating a slab that is too wet leads to blistering and delamination.

Why should glossy or previously enamel-painted surfaces be 'de-glossed' before recoating?

• a.A dull, abraded surface gives the new coat a better mechanical bond✓
• b.It adds gloss to the finish coat
• c.It removes the need to clean the surface
• d.It changes the color of the substrate permanently

Sanding or using a liquid deglosser scuffs a slick, glossy surface so the new coat can grip it mechanically. Painting over an untreated high-gloss surface often results in poor adhesion and peeling. Cleaning to remove contaminants is still required in addition to deglossing.

Bare ferrous (iron/steel) metal should be primed with what type of primer to prevent corrosion?

• a.A drywall sealer
• b.A masonry block filler
• c.A rust-inhibitive metal primer✓
• d.A latex wood primer only

Ferrous metals rust when exposed to moisture and oxygen, so a rust-inhibitive (corrosion-resistant) primer is used to protect the steel and provide adhesion for the topcoat. Block fillers and drywall sealers are formulated for masonry and gypsum, not metal. Surface rust should be removed before priming.

What is the purpose of a primer/sealer on new, unpainted drywall?

• a.To make the wall glossy
• b.To equalize porosity between the paper and joint compound so the finish coat looks uniform✓
• c.To replace the need for taping joints
• d.To add texture to the finish

New drywall has paper facing and joint compound with different absorption rates; without a sealer the finish coat flashes and shows joints. A drywall primer/sealer (PVA primer) evens out porosity so the topcoat dries to a uniform sheen. It also improves adhesion of the finish coat.

Loose, flaking paint on old siding should be handled how before recoating?

• a.Painted over immediately to lock it down
• b.Left in place because it improves adhesion
• c.Covered with heavy caulk
• d.Scraped and/or sanded to a sound, tightly adhered edge, then feathered smooth✓

New paint is only as sound as the surface beneath it, so loose and flaking paint must be scraped off to firmly bonded material. Edges are then sanded (feathered) to blend the transition. On pre-1978 homes this work must follow lead-safe practices.

Why is it poor practice to paint over a wall contaminated with grease or oil?

• a.It makes the paint dry too fast
• b.The contaminant prevents adhesion, causing the paint to peel or fisheye✓
• c.It permanently changes the paint color
• d.It increases the film thickness needed

Grease and oil act as a bond-breaker, so paint cannot adhere and may crawl into 'fisheyes' or peel. Surfaces such as kitchen walls should be degreased with a suitable cleaner and rinsed before priming. Clean, dry, dull, and sound is the standard rule for a paint-ready surface.

New galvanized (zinc-coated) steel often needs what preparation before painting to avoid adhesion failure?

• a.Coating immediately while still oily
• b.Applying block filler
• c.Cleaning to remove oils and using a primer compatible with galvanized metal (or allowing weathering)✓
• d.Sanding it to bare steel

Fresh galvanized surfaces carry oils and a smooth zinc layer that ordinary paint will not grip, so oil-based paints may peel. The surface should be cleaned of oils and coated with a primer formulated for galvanized metal. Some specifications allow the metal to weather before painting.

When patching a larger hole in drywall, why is joint compound often applied in multiple thin coats rather than one thick coat?

• a.Thin coats dry more evenly and shrink/crack less than one thick coat✓
• b.Thin coats change the wall color
• c.One thick coat is always stronger and preferred
• d.Thin coats eliminate the need for sanding

Thick applications of joint compound shrink, crack, and take much longer to dry. Building up the repair in thin, progressively wider coats produces a flat, crack-free patch that feathers into the surrounding wall. Each coat is allowed to dry and is sanded or wiped before the next.

What is the main reason to remove dust after sanding and before painting?

• a.Dust improves paint flow
• b.Dust left on the surface prevents proper adhesion and creates a gritty finish✓
• c.Dust changes the sheen of the paint can
• d.It is only an aesthetic preference with no effect on adhesion

Sanding dust acts as a contaminant that keeps paint from bonding and leaves a rough, gritty film. Wiping with a tack cloth, vacuuming, or damp-wiping removes the dust for a clean bond and smooth finish. This step is part of preparing a clean, sound surface.

Knots and sap streaks in bare softwood can bleed through paint unless they are sealed with what?

• a.A thin coat of water
• b.Only the finish paint
• c.A stain-blocking primer (such as shellac-based or a dedicated knot sealer)✓
• d.A coat of clear caulk

Resin and tannins in knots and sap can bleed through ordinary paint, leaving yellow-brown stains. A stain-blocking primer, often shellac- or oil-based, seals the knot so it does not discolor the finish. Spot-priming the knots before the full prime coat is common practice.

Why should exterior wood be checked for moisture content before painting?

• a.Dry wood cannot be painted at all
• b.Painting wood that is too wet traps moisture and causes blistering and peeling✓
• c.Moisture makes the paint cure harder
• d.Wet wood improves paint penetration

Excess moisture in wood pushes outward as it dries and lifts the paint film, causing blisters and peeling. Wood should generally be below roughly 15% moisture content before painting. A moisture meter provides a reliable reading before coating.

What is 'feathering' when preparing a spot repair on a painted surface?

• a.Sanding the edges of the repair so the transition to the surrounding paint is smooth and invisible✓
• b.Adding feathers to the texture
• c.Applying a thick ridge of paint at the repair edge
• d.Removing all paint from the entire wall

Feathering sands or tapers the edge of a patched or scraped area so there is no visible ridge between old and new material. A feathered edge lets the primer and finish blend seamlessly. Without feathering, the repair outline telegraphs through the finish coat.

When dry-cutting or grinding concrete during prep generates dust, what airborne hazard is of concern under Cal/OSHA?

• a.Lead only
• b.Asbestos only
• c.Respirable crystalline silica✓
• d.Carbon monoxide

Cutting, grinding, or abrading concrete and masonry releases respirable crystalline silica, which can cause silicosis. Cal/OSHA requires engineering controls such as water suppression or vacuum dust collection and, when needed, respiratory protection. This applies to prep work as well as demolition.Cal/OSHA Title 8

Before applying an elastomeric coating to a stucco crack, what prep step is typically needed?

• a.Wetting the crack with solvent
• b.Cleaning and filling/bridging the crack and ensuring the surface is sound and dry✓
• c.Applying gloss enamel first
• d.Sanding the entire wall to bare masonry

Elastomeric coatings bridge hairline cracks but the substrate must first be clean, sound, and dry, with larger cracks filled or reinforced. Loose material and contaminants would cause the thick coating to fail. Proper prep lets the elastomeric film stretch over the crack without delaminating.

Why is it important that a masonry surface be fully cured before painting with most coatings?

• a.Fresh masonry is highly alkaline and can chemically attack (saponify) some paints✓
• b.Cured masonry cannot hold paint
• c.Fresh masonry is too smooth to paint
• d.Curing changes the color of the paint

New concrete and masonry are strongly alkaline while curing, and this alkalinity can break down oil-based coatings, a reaction called saponification. Allowing the masonry to cure (often about 28 days) and/or using an alkali-resistant primer prevents coating failure. Testing surface pH can confirm readiness.

A previously painted surface shows widespread peeling down to bare wood. What does this MOST likely indicate?

• a.The previous paint was too expensive
• b.The surface was overly clean
• c.A prep or moisture problem such as painting over a dirty, wet, or unprimed surface✓
• d.The paint color was too light

Peeling to bare substrate points to an adhesion failure, usually from painting over a dirty, glossy, damp, or unprimed surface, or from underlying moisture. Correcting the cause and properly preparing and priming the wood is required before recoating. Simply repainting without addressing the cause repeats the failure.

What is the correct order of the basic surface-prep steps for a typical repaint?

• a.Prime, clean, scrape, sand
• b.Clean, scrape/remove loose paint, sand/patch, then prime✓
• c.Sand, prime, clean, scrape
• d.Prime, sand, clean, scrape

A logical prep sequence is to clean the surface, remove loose and failing paint, sand and patch defects, and then prime bare areas. Cleaning first prevents grinding contaminants into the surface, and priming last seals the prepared substrate. Following this order produces a sound base for the finish coats.